Prestige classes are specialized character classes available to PCs and NPCs after achieving certain prerequisites. Most prestige classes require some degree of instruction, as well.
Prestige Class Availability
Dwarven War College: Dwarven Defender
Travelers: Hospitalier, Templar
Alexandrian Universities*: Mystic Theurge , Archmage, Loremaster , Thaumaturgist , Artificer, Choirist
Petran Universities: Loremaster , Shadowdancer , Red Wizard (See DMG), Artificer
Alexandrian Church: Hospitalier, Hierophant , Loremaster , Mystic Theurge , Artificer
Druid Hierophant: Hierophant 
National/Racial Prestige Classes: Gnomish Infiltrator, Odessan Field Marshall, Halfling Dog Rider, Fresian War Master, Celesti Rageblade, Flannari Cavalier, Petran Blade Dervish, Petaran Camel Archer, Alexian Sentinel
No Training Required: Dragoman, Blackguard, Arcane Trickster, Duelist , Eldritch Knight , Horizon Walker  (Lvls 1-5)
No known Availability: Arcane Archer, Assassin, Dragon Disciple, Horizon Walker (Level 6-10),Elk-Rider
- Availability of a specific class is not guaranteed at any individual university.